Switch to standard integer types in ios/.

ios/chrome/browser/browser_state_metrics/browser_state_metrics.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ios/chrome/browser/browser_state_metrics/browser_state_metrics.h"
 
+#include <stddef.h>
+
 #include "components/profile_metrics/counts.h"
 #include "ios/chrome/browser/browser_state/browser_state_info_cache.h"
 #include "ios/public/provider/chrome/browser/browser_state/chrome_browser_state_manager.h"
 
 bool CountBrowserStateInformation(ios::ChromeBrowserStateManager* manager,
                                   profile_metrics::Counts* counts) {
   BrowserStateInfoCache* info_cache = manager->GetBrowserStateInfoCache();
   size_t number_of_browser_states = info_cache->GetNumberOfBrowserStates();
   counts->total = number_of_browser_states;
 
   // Ignore other metrics if we have no browser states.
   if (!number_of_browser_states)
     return false;
 
   for (size_t i = 0; i < number_of_browser_states; ++i) {
     if (info_cache->BrowserStateIsAuthenticatedAtIndex(i)) {
       counts->signedin++;
       if (info_cache->BrowserStateIsAuthErrorAtIndex(i))
         counts->auth_errors++;
     }
   }
   return true;
 }
 
 void LogNumberOfBrowserStates(ios::ChromeBrowserStateManager* manager) {
   profile_metrics::Counts counts;
   CountBrowserStateInformation(manager, &counts);
   profile_metrics::LogProfileMetricsCounts(counts);
 }